This invention relates to terminal blocks and more particularly to terminal blocks which use insulation displacement connectors (IDCs) and are environmentally sealed.
Terminal blocks are used in the telephone industry to provide a connection between the tip and ring conductors of one group of telephone wire pairs and the tip and ring conductors of another group of telephone wire pairs. The blocks are often installed in equipment such as pedestals and aerial splice closures which are used outdoors. Therefore, such blocks may be exposed to environmental conditions such as high humidity and heavy rain which can lead to corrosion of both the terminals provided in the block to make the connection as well as the connections themselves.
Corrosion of the telephone wire connections interferes with service to the telephone company subscribers. Such interference may take many forms depending on the extent of the corrosion. For example, the corrosion may give rise to excessive noise on the telephone line or loss of signal strength. No matter what form the interference takes, if it results from corrosion of the wire connections at the block, it will require the cleaning of the connections and of the terminals of the block. The telephone operating company must then send a craftsperson to the site where the terminal block is located to do the cleaning. If the terminal block site is in a corrosion promoting location, e.g., near the seashore, that may lead to frequent visits to the site by the craftsperson to clean the connections.
To avoid the above subscriber service problems and the expense of sending a craftsperson to clean the connections, it may be desirable that terminal blocks provide connections which are environmentally sealed. In addition to being environmentally sealed, the terminal blocks should also be capable of retrofit installation in existing equipment, such as pedestals and aerial closures, where blocks which are not environmentally sealed are now used. The environmentally sealed blocks should have the capability of providing the same number of total connections as the non-environmentally sealed blocks provided. In other words, the environmentally sealed blocks should be a direct replacement for the non-environmentally sealed blocks.
Environmental sealing can be provided by using any one of a number of different types of reenterable encapsulants such as a grease or a gel. It is desirable that the environmentally sealed terminal block be designed so that it is capable of using either grease and/or some other encapsulant such as a gel. It is further desirable that if grease is used either in whole or in part as the encapsulant that the block include means to retain the grease adjacent the terminals or other connection means and the connections even if the connection means and/or connections have to be accessed by a craftsperson.